EP0972431B1 - Particle manipulation - Google Patents

Description

The invention relates to a method and a device for Manipulation of microscopic particles, in particular for Manipulation of particles in a plasma crystalline state.

It is known that microscopic solid particles in a Plasma in a macroscopically regular arrangement as can align so-called plasma crystal. The properties of plasma crystals are described, for example, by H. Thomas et al. in "Phys. Rev. Lett." Volume 73, 1994, page 652, et seq., or by H. Thomas & G. E. Morfill in "Nature" volume 379, 1996, Page 806, ff., Described.

A quantitative description of plasma crystals on the Basis of molecular-dynamic simulations of Yukawa systems and a distinction from "liquid" states is described by S. Hamaguchi et al. in "Physical Review E", Volume 56, 1997, p. 4671 et seq. This publication was after published on the priority date of the present application. The demarcation between a plasma-crystalline and a Non-plasma crystalline (eg liquid) state occurs the basis of a phase diagram, the abscissa by a dimensionless parameter κ as a quotient of the charge-dependent Distance of the particles and the so-called Debye length and whose ordinate is formed by a parameter Γ which dimensionless describes the Coulomb interaction of the particles. Since the abscissa and ordinate parameters are dependent from the operating parameters of the plasma can thus state changes the plasma states of the particles by changes the operating parameters are achieved.

Important aspects of plasma crystal formation are described in The following with reference to a conventional arrangement for training of a plasma crystal according to FIG. 14.

A gas comprises in the plasma state, for example, by a Glow or gas discharge is generated, variously charged Particles, such as positively or negatively charged ions, electrons and radicals, but also neutral atoms. Are located in the plasma microscopic particles (order of magnitude μm), for Example dust particles, so they are electrically charged. The charge can vary depending on the particle size and the Plasma conditions (gas type, plasma density, temperature, pressure etc.) reach a few hundred thousand electron charges. at suitable particle and plasma conditions form between the charged particles Coulomb forces under which Effect the particles the plasma crystalline state as two- or take three-dimensional arrangement. It plays alongside The Coulomb forces also an energy deprivation of the particles due to collisions with neutral atoms in the plasma.

An arrangement for the formation of plasma crystals is exemplary shown in Fig. 14 (see also the above Publication in Phys. Rev. Lett.). In a reactor (vessel walls not shown) with a carrier gas are two plane Discharge electrodes arranged one above the other. The lower one circular or disc-shaped RF electrode 11 is provided with a AC voltage controlled, the upper annular counter electrode 12 is z. B. grounded. The electrode distance is approx. 2 cm. A control circuit 13 is adapted to the RF generator 14 to connect to the RF electrode 11 and the grounding and disconnecting circuit 15 of the counter electrode 12 to drive. The high frequency energy, for example, with a Frequency of 13.56 MHz and an output of approx. 5 W coupled become. The carrier gas is made by noble gases or reactive Gases formed at a pressure of about 0.01 - 2 mbar. About a (not shown) Staubdispensor become dust particles introduced into the reactor. Arrange the dust particles behave as a plasma crystal in an equilibrium state, in the gravitational force G acting on the particles electric field force E is balanced by a DC field in the vicinity of the RF electrode 11 on the Dust particles is exercised depending on their charge. If it is a monodisperse dust size distribution, so the plasma crystal arrangement takes place either as a monolayer in a plane, or as a multi-layered state in training 3-dimensional plasma crystals. The plasma crystal is under illumination up to a particle size of about 1 micron with recognizable to the naked eye. The visualization of the plasma crystal is through a side-mounted helium-neon laser 16 improves its beam with a cylindrical lens combination 16a on the size of the lateral crystal expansion with a thickness of approx. 150 microns is fanned out. The observation of the plasma crystal is carried out with a CCD camera 17, the provided with a magnifying macro-optics 18 and by a Image processing 19 is controlled, which also works with the laser 16 communicates.

The behavior of microscopic particles in plasmas is of high theoretical and practical interest. The theoretical Interest is particularly related to the plasma crystals and their state changes. The practical interest is derived from the fact that plasma reactors used in coating or processing methods (in particular in semiconductor technology) be used, an electrode assembly according to Fig. 14 have.

In previous arrangements for the investigation of plasma crystals were the means of influencing the plasma crystals on the type of particles used and the plasma conditions realized limited. A means of targeted and site-selective Handling of plasma crystals is not yet available so far no practical use for Plasma crystals was known.

DE 44 12 902 A1 discloses a method for increasing the coating rate and to reduce the dust density in one Plasma discharge space and a plasma chamber known. In one Plasma process space is along the surface of a machined Workpiece set a predetermined dust density. The position of the workpiece in the plasma process space is changeable by a sliding bracket.

The object of the invention is a method of manipulation of particles in plasmas, in particular for influencing the particle itself or to modify a substrate surface, and an apparatus for realizing the Specify method.

This object is achieved by methods having the features according to claim 1 or 2 or a device with the features solved according to claim 10. Advantageous embodiments The invention will become apparent from the dependent Claims.

The invention is based on the following basic findings. The properties of a plasma crystal, in particular The geometric shape depends not only on the properties of the Plasma or the particles from. Rather, it is possible the figure a plasma crystal, in particular the shape of the outer Outline or cross-sectional shape through a location-selective Influencing the above balance between gravitational forces and modify electrical forces. For this the external forces acting on the particles for example by a location-dependent change of a static, quasi-static or low-frequency variable electric field between the electrodes of a plasma reactor, by a site-selective particle discharge or by a site-selective particle irradiation varies (action of adjusting forces). In this way, particles in the Plasma on any curved surfaces with any borders arrange in a plasma crystalline state. The particles in the plasma can thus be moved in a predetermined manner, this movement is reversible, so that the plasma-crystalline Condition even between different shapes umstellbar is.

Another important aspect of the invention is in that by the site-selective deformation of a plasma crystal different subregions of the plasma crystal different Plasma conditions are exposed. This will in particular in a plasma between two substantially planar ones Electrodes are a site selective plasma treatment of parts of the Plasma crystal (e.g., coating or ablation) is possible. Such a site-selective particle treatment may be connect a plot to a substrate.

Furthermore, there is an important aspect of the invention in that the formation of a plasma crystalline state by the presence of a substrate in a plasma reactor, in particular between reactor electrodes to form a Glow or gas discharge, is unaffected. It is special possible, the above-mentioned switching operations in the immediate Near a flat, flat or curved substrate and then measure the distance between the particles in the plasma crystalline state and the substrate surface reduce so that at least one predetermined part the particles are applied to the substrate surface. The reduction in distance can either by influencing the Field forces that hold the particles in position, or through Movement of the substrate surface done. Thus, particles can in plasma-crystalline state in arbitrarily designed patterns deposited on substrate surfaces. In order to the invention provides a novel site-selective, mask-free Coating process prepared with the modified Surfaces are generated. Due to the applied particles the modified surfaces have altered electronic, optical and / or mechanical properties. It is but also possible, the site-selectively applied particles even for masking or conditioning the substrate surface before a subsequent further coating step to use.

An inventive device for manipulating particles in the plasma crystalline state comprises a reaction vessel, the means for forming a plasma and at least one Contains substrate. The means for the formation of the plasma become preferably by flat, substantially parallel electrodes formed, in the space between which the substrate is movable is. The electrodes in the reaction vessel can field-forming Structures for the site - selective influence of the particles in the have plasma crystalline state. In the reaction vessel can and means for site-selective particle discharge (e.g., UV exposure means with a masking device), means for applying a radiation pressure to the particles, observing means and control means.

A particular aspect of the invention is the design the electrodes for the site-selective influencing of the particles in the reaction vessel. According to the invention, an electrode device (or: adaptive electrode) indicated that a variety of electrode segments simultaneously with a High-frequency voltage and each individually with a specific DC or low frequency voltage applied are. The high frequency voltage is set to a Create or maintain plasma state in the reaction vessel, while the DC or low frequency voltage to do so is set up, in the reaction vessel a static or slow to produce variable field distribution, under the effect of which the particles arrange or move in the reaction vessel. Other important features of the adaptive electrode are the formation of a miniaturized electrode segments (Dot electrodes) formed matrix arrangement, the design the matrix arrangement as a substantially planar, layered Component whose electrode side points to the reaction vessel and the back of which carries control electronics which Pressure relief of the component z. B. by forming a negative pressure in the room to which the back of the electrode device points, and the provision of a tempering device for the control electronics.

Fig. 1

eine schematische Seitenansicht einer erfindungsgemäßen Anordnung zur Manipulierung von Teilchen in einem plasmakristallinen Zustand;

Fig. 2

eine schematische Draufsicht auf einen Teil der Anordnung gemäß Fig. 1;

Fig. 3

eine Draufsicht auf einen Ausschnitt eines Plasmakristalls im freien bzw. adsorbierten Zustand zur Illustration der erfindungsgemäßen Beschichtungstechnik;

Fig. 4

eine schematische Illustration einer erfindungsgemäßen Elektrodengestaltung zur Manipulierung von Plasmakristallen, und Beispiele einer ortsselektiven Substratbeschichtung;

Fig. 5

eine Explosionsdarstellung eines mit einer erfindungsgemäßen adaptiven Elektrode versehenen Reaktionsgefäßes;

Fig. 6

eine schematische Draufsicht auf eine adaptive Elektrode gemäß Fig. 5;

Fig. 7

eine schematische Perspektivansicht einer Subeinheit der in den Figuren 5 und 6 dargestellten adaptiven Elektrode mit der zugehörigen Schaltelektronik;

Fig. 8

eine Blockdarstellung zur Illustration der Steuerelektronik einer erfindungsgemäßen adaptiven Elektrode;

Fig. 9

eine schematische Illustration eines weiteren Beispiels einer ortsselektiven Substratbeschichtung;

Fig. 10

eine Darstellung zur Illustration eines weiteren Beispiels einer ortsselektiven Substratbeschichtung;

Fig. 11

eine schematische Draufsicht auf eine modifizierte Anordnung zur Manipulierung von Plasmakristallen und ein weiteres Beispiel einer ortsselektiven Substratbeschichtung;

Fig. 12

eine schematische Illustration einer Substratbeschichtung mit sogenannten Bucky Tubes;

Fig. 13

eine schematische Draufsicht auf eine weitere Ausführungsform einer erfindungsgemäßen Anordnung zur Manipulierung von Plasmakristallen; und

Fig. 14

eine schematische Perspektivansicht eines herkömmlichen Reaktors zur Bildung von Plasmakristallen (Stand der Technik).

Details and advantages of the invention will be described below with reference to the accompanying drawings. Show it:

Fig. 1

a schematic side view of an inventive arrangement for manipulating particles in a plasma crystalline state;

Fig. 2

a schematic plan view of a portion of the arrangement of FIG. 1;

Fig. 3

a plan view of a section of a plasma crystal in the free or adsorbed state to illustrate the coating technique of the invention;

Fig. 4

a schematic illustration of an electrode design according to the invention for the manipulation of plasma crystals, and examples of a site-selective substrate coating;

Fig. 5

an exploded view of a provided with an inventive adaptive electrode reaction vessel;

Fig. 6

a schematic plan view of an adaptive electrode of FIG. 5;

Fig. 7

a schematic perspective view of a subunit of the adaptive electrode shown in Figures 5 and 6 with the associated switching electronics;

Fig. 8

a block diagram illustrating the control electronics of an adaptive electrode according to the invention;

Fig. 9

a schematic illustration of another example of a site-selective substrate coating;

Fig. 10

a representation for illustrating a further example of a site-selective substrate coating;

Fig. 11

a schematic plan view of a modified arrangement for manipulating plasma crystals and another example of a site-selective substrate coating;

Fig. 12

a schematic illustration of a substrate coating with so-called Bucky Tubes;

Fig. 13

a schematic plan view of another embodiment of an inventive arrangement for the manipulation of plasma crystals; and

Fig. 14

a schematic perspective view of a conventional reactor for the formation of plasma crystals (prior art).

The invention will be described below using the example of a plasma arrangement described, which comprises a reaction vessel as a reactor, its construction in terms of plasma generation and plasma crystal observation essentially the conventional structure corresponds as described above with reference to FIG. 14 has been. However, it is understood by the skilled person that also different constructed reactors can be used as far as they are concerned for the inventive manipulation of particles in the plasma-crystalline Condition are set up.

The schematic side view of an arrangement for manipulation of plasma crystals according to FIG. 1 shows an HF electrode 11, a grounded counter electrode 12, a control device 13, an RF generator 14, a switching device 15, an observation light source 16 with a cylindrical lens arrangement 16a, an observation means in the form of a CCD camera 17 with a magnifying optics 18 and an associated control device 19. For very small (<100 nm) particles becomes another Observing agents required (e.g., using the Bragg scattering). A dust dispenser 21 with a reservoir 22, a conditioning device 23 and an inlet means 24 is set up to place particles in the space between the RF electrode 11 and the counter electrode 12 introduce. The conditioning device 23 may, for example, a Precharging device for the particles included.

The arrangement according to the invention further comprises a substrate 30, that with an adjustment 30 in all directions is mobile. FIG. 1 does not show the wall of the reaction vessel, which forms a closed space for the carrier gas and vacuum-tight the electrodes 12, the substrate 30 and Includes parts of the particle delivery device. The wall may further comprise windows for radiation input and output.

Figure 2 shows schematically a plan view of parts of the invention Arrangement according to FIG. 1, namely the HF electrode 11 and the substrate 30 with the adjusting device 31. In addition is an unloading device 24, not shown in Fig. 1 shown for the site-selective discharge of particles in the plasma-crystalline state is established. When presented For example, the unloader 24 includes a UV light source 25 and an imaging and masking system 26, irradiated with the parts of the plasma crystal and under action the UV radiation can be discharged.

In the following, a first embodiment of the invention Procedure for manipulating the particles in the plasma explained with reference to Figures 1 and 2.

In (not shown) reaction vessel, in particular between the RF and counter electrodes, which act as discharge electrodes, a plasma is ignited in a carrier gas. A special Advantage of the invention is that of the type of Carrier gases are no special requirements. The plasma conditions (type and density of the gas, RF power, Frequency, pressure etc.) can be made by the professional according to the conditions the plasma arrangement and the desired crystal properties to be selected. That can, for example, too Low energy argon charges or silane discharges among the Conditions, as in the case of plasma deposition in semiconductor technology to be used. The use of a reactive gas such as. Silane is for further treatment steps on Plasma crystal of advantage. Energy of ions in plasma corresponds essentially to the gas temperature. This is going through the discharge conditions and optionally by an external Cooling determined. Thus, for example, in an inventive Arrangement of a (not shown) nitrogen cooling be provided.

About the dust dispenser 21 are the particles to be manipulated introduced into the electrode space. The particle size is in the range of 20 nm to 100 μm. The lower limit of the Particle size is determined by the pressure conditions in the reaction vessel and about charging. The particles must be like that be difficult, that in the plasma-free state, the particles under Effect of gravity to perform a vertical movement and do not remain in limbo. The upper limit of the particle sizes is due to the so-called Debye length between the set adjacent particles. The Debye length increases proportionally to the root of the plasma temperature or inversely proportional to the root of the plasma density. Another special Advantage of the invention is that in addition to the size requirements no further to the particles to be manipulated Restrictions on the shape or material of the Particles exist. They are any, e.g. round, needle-shaped, tubular or plate-shaped particles usable. The Particles must be solid or have sufficient dimensional stability under the plasma conditions. It is preferably a Material used, in the particle size range of interest has special electrical or optical properties. It can also be used a material that has a Composition of various substances, e.g. organic Fabrics, is.

The particles introduced into the plasma form a plasma crystal 10 (see Figures 1, 2). The plasma crystal is through a level, area, regular particle arrangement characterized. The particle assembly may be a monolayer, as shown below Referring to Fig. 3 is explained, a multilayer or to be a three-dimensional structure.

The RF electrode has a negative DC voltage. at a diameter of the electrodes of approx. 8 to 10 cm, one Electrode distance of approx. 2 cm and a preload on the HF electrode 11 of approx. -15 volts, for example, arrange themselves Polymer particles of a characteristic size of approx. 7 μm as a flat cloud with a distance of approx. 0.5 cm from the HF electrode 11 on.

The dimensions given here by way of example change changed electrode parameters (electrode diameter, electrode distance, Voltage values) accordingly. The electrode diameter can be in the range of a few centimeters, for example up to 60 cm and the electrode distance can be in the range of 1 cm to 10 cm. There are preferably such electrode parameters selected with available and CVD reactors are compatible.

The substrate 30 is between the RF electrode 11 and the plasma crystal 10 arranged. Also in relation to the substrate material and the substrate shape are advantageously none Restrictions. In particular, it can be both a conductive as well as a non-conductive substrate without that the conditions for plasma crystal formation change.

In a method according to the invention for the manipulation of Particles is first an adjustment of the particles in one Treatment position. This treatment position can the Equilibrium state upon formation of the plasma crystal after Introduce the particles into the reactor. It is but also possible to move the plasma crystal 10, in particular the relative position with respect to the electrodes or the To change substrate. This is done, for example, by a change the plasma conditions. Thus, by changing the Carrier gas density, a change in the particle charge and thus a Change in the state of equilibrium between gravitational force and electrical power can be achieved. The same applies when changing the negative bias of the RF electrode or at an external discharge of the particles. In the treatment position will be at least one in a next step Part of the particles of a plasma treatment or a plot subjected to the substrate.

The plasma treatment may, for example, be a particle surface coating or removal. In the latter Case, for example, a gradual lowering of the plasma crystal to a lesser height above the RF electrode lead that the lowest layers of the plasma crystal one be subjected to selective plasma etching process. For particle coating If necessary, a plasma change can be made while the reactor is in operation be provided.

For application to the substrate 30 may be any suitable change the distance between the plasma crystal and the substrate surface be used. According to a first alternative becomes the plasma crystal by changing the plasma conditions lowered to the substrate. According to a second alternative is Substrate with the adjustment device 31 to the plasma crystal raised. According to a third, preferred alternative the discharge between the electrodes is switched off, so that the Plasma goes out and the particles fall onto the substrate. At the Contact between the particles and the substrate lead molecular Attractive forces for adsorption of the particles on the substrate surface. In the further process, the particle adsorption be reinforced by an overlay.

FIG. 3 shows the result of a particularly simple example Particle application to the substrate surface accordingly the third alternative mentioned above. It is one Plasma-crystalline monolayer, as with the image pickup device 17 can be observed in a free-hanging Condition in the plasma (structures with unfilled border) and in the adsorbed state (structure with filled border) on one Substrate after expiration of the plasma shown. The particle dimensions amount to approx. 5 to 10 μm at distances of approx. 200 or 300 μm. The inventors have found for the first time that in this particularly simple application of the particles on the substrate the regular arrangement almost completely is preserved as this is the minimum deviations between the particle position in the suspended or adsorbed state ieigen. Because of this property, it is possible microscopic Particles with high accuracy on a substrate surface to place.

Fig. 4 shows a schematic side view of a detail an inventive arrangement for particle manipulation. Between the RF electrode 11 and the substrate 30 with the adjusting device 31 on the one hand and the grounded counter electrode 12, particles are arranged in the plasma-crystalline state. The plasma crystal 40 is multi-curved in cross-sectional shape formed essentially the course of the static electric field in the space between the electrodes equivalent. The field between the electrodes is replaced by a Electrode structuring 41 site-selectively deformed. When presented An example is the electrode structuring by means of additional electrodes 41 (needle electrodes) formed with a positive voltage applied and isolated by the counter electrode 12 are performed. The plasma crystal follows the site-selective deformation of the electric field, so that the multi-arched crystal form is formed. The additional electrodes 41 can be arranged in rows or areas be. Instead of a positive potential, the additional electrodes 41 also subjected to a negative potential be.

In the lower part of Fig. 4 are two examples of a location-selective Substrate coating with a manipulated according to the invention Plasma crystal shown schematically. Done one Formation of the plasma crystal such that the crystal cross-sectional shape pointing upwards bulges, so leads an approximation of the plasma crystal to the substrate 30 according to the above first or second alternative to a Coating pattern corresponding to the lower left part of Fig. 4. Conversely, a downwardly facing bulge set (by negative potentials of the additional electrodes 41), so the mutual approach leads to an island-like Coating according to the lower right part of Fig. 4.

By a suitable shaping of the electrode structuring or The additional electrodes can be any coating pattern e.g. in the form of circles, rings, bows, stripes or the like. form on the substrate surface. Additional modifications are possible if the additional electrodes according to FIG. 4 are movably arranged, so that the manipulation of the plasma crystal 40 can be varied over time. Accordingly Different coating patterns can be consecutive on the substrate 30.

An alternative design for the location-selective deformation of Field between the electrodes will be referred to below explained on the figures 5 to 8.

Fig. 5 shows an exploded view of a reaction vessel 20, which is set up for the realization of the invention. The Reaction vessel 20 is not only explained in the following adapted adaptive electrode, but can also in conjunction with the embodiments shown in the other figures realized the invention. The reaction vessel 20 is made from an electrode receptacle 201, which is in the recipient bottom 202 is inserted. The reaction space is from the recipient bottom 202 with the electrode holder 201, the recipient wall 203 and the recipient lid 204 and is over the vacuum port 205 can be evacuated. The recipient lid 204 has a window insert 206 on one, if necessary relative to the recipient cover 204 rotatable vacuum-tight Subunit 207 of the recipient cover 204 is attached. It can be provided that the subunit 207 itself under vacuum is rotatable. The window insert 206 is for recording different means of observation or diagnosis for the Reaction space designed manipulated particles. The parts of the Reaction vessel 20 are in the usual manner as in a vacuum vessel connected. Furthermore, over lateral Flan units additionally different diagnostic units be introduced.

In Fig. 5 are further the adaptive RF electrode 11 and the grounded Counter electrode 12 (see Fig. 1) shown. The counter electrode 12 is annular to an observation port for the observation means (not shown).

An enlarged plan view of the adaptive electrode 11 is shown in Fig. 6. The adaptive electrode 11 has accordingly the usual cylindrical design of vacuum vessels to form one by external recipient internals as undisturbed field course a substantially circular Outline 111. Within the border are one Ring electrode 112 and a plurality of electrode segments, in the example shown in electrode subunits 113th are summarized. The ring electrode 112 is in one piece, continuous electrode area shown and field correction (Flattening) of the electric field of the highly segmented Set up electrode area. It is, however, a substitute also possible, instead of the ring electrode 112 a provide segmented electrode area, but in which the Segments are subjected to identical fields. In the transition area between the electrode subunits and the ring electrode the subunits are changed in height so that the ring (possibly milled from the bottom) can be pushed over the subunits.

The electrode subunits 113 are in an inner; of the Ring electrode 112 surrounding region of the electrode 11 is provided and each include a plurality of electrode segments. The shape, size and number of electrode segments becomes application dependent depending on the spatial requirements of a electric DC or low frequency field (E) between the Electrodes 11, 12 (see Fig. 1) constructed. The greatest variability The adjustable field characteristics is determined by a matrix arrangement a plurality of punctiform electrode segments (hereinafter referred to as dot segments or dot electrodes designated) reached. Here, the term punctiform means Electrode segment or point segment, although each Electrode element indicative of a reaction space finite Surface has, but this much smaller dimensions as the total size of the electrode 11 has. Everybody owns that Point electrode, for example, a characteristic length dimension, by a factor of about 1/500 to 1/100, e.g. 1/300, compared to the outer dimension (diameter) of the electrode 11 is reduced. However, the matrix grid may be application-dependent also be chosen larger. At the here shown Dot-matrix form of the adaptive electrode is a characteristic Length dimension of the point electrode preferably equal to or less than the Debye length of the particles in the plasma (eg around 3 mm).

An adaptive electrode 11 has, for example, an outer diameter of about 50 cm with a width of the ring electrode 112 of about 5 cm, so that the inner region of the electrode segments 113 has a diameter of about 40 cm. The adaptive Electrode subunits 113 may be used in their entirety For example, comprise about 50,000 to 100,000 dot segments. A preferred measure of segmentation is a 1.27 mm grid, compatible with available 1/20-inch connector devices is, as explained below with reference to FIG. 7 in more detail becomes. In this case, can be within the ring electrode 112 about 80,000 electrically isolated point segments Arrange.

For reasons of clarity, the lower part of FIG. 6 shows not every single point segment, but the electrode subunits (Point segment groups). The groupwise summary of dot segments is not a mandatory feature of the invention, but has advantages in the electrode control, as described in detail below with reference to Figures 7 and 8 will be explained. This is how the line pattern in the lower part shows of FIG. 6, for example, electrode subunits 113, each 8 x 32 dot segments included. This is through the top Part of Fig. 6 illustrates that a partial enlargement (X) from the edge of the electrode subunits 113. The invention is not limited to the summary of 8x32 Point segments to an electrode sub-unit limited, but may be other groupings depending on the design and application include (eg 16 x 16 dot segments).

The upper part of Fig. 6 shows an example highlighted Electrode subunit 113 having a plurality of dot segments or point electrodes 115, each one below the other are electrically isolated from each other by isolation bridges. The point electrodes 115 have facing the reaction space, square faces of width a = 1.25 mm. The isolation bridges 116 have a width b = 0.02 mm, so that overall gives the above 1.27 mm grid. The electrode subunit 113 includes e.g. 8 x 32 point electrodes 115. From Fig. 6 it is further apparent that the ring electrode 112 and the region of the electrode subunits 113 are mutually exclusive overlap. This is an optimal, dense filling of the inner region of the electrode 11 also at the edge of the ring electrode 112, as in the enlarged part of FIG. 6 is recognizable.

Both the ring electrode 112 and the electrode subunits 113 consist of a metallic electrode material.

The material will be application dependent and according to the desired Manufacturing method selected for the electrode. Both below explained etching process can be used as electrode material e.g. Stainless steel, aluminum or copper can be used. to Avoidance of electrical disturbances due to deposits the electrode surface is preferably this with an insulating layer coated, e.g. from the same insulation material how the isolation webs 116 exists. The insulation layer For example, a thickness of about 10 microns to 100 μm, preferably 20 μm. As insulation material of the Isolation webs 116 is suitable for any material that in the occurring voltage values sufficient insulation resistance granted between the point electrodes. This insulation material For example, epoxy resin or another is more suitable Plastic.

Fig. 7 shows the structure of the segmented electrode by way of example an electrode sub-unit 113. According to the above explained example, the electrode subunit 113 again by way of example 8 × 32 point electrodes 115. These form (together with the other, not shown segments of the adaptive electrode) also has an upper electrode area is referred to as a segmented electrode 120. The segmented Furthermore, the electrode consists of the insulation plate 122, in which a plurality of sockets are incorporated (not shown), the number and arrangement of each of the Point electrodes 115 of the electrode subunit 113 corresponds. The sockets are designed to receive plug units 123, possibly also as an integral base plate can be trained. There is also the possibility of the Plug units 123 interpreted as sockets and an electrical Connection with the sockets, which are in the insulation plate are integrated to produce via conductive pins. Between each socket of the insulating plate 122 and the corresponding Point electrode 115 is in electrical contact.

The structure of the insulation plate 122 depends on the manufacturing method the total electrode 11 and the area the electrode subunits 113. Such a manufacturing method is illustrated below by way of example.

First, from the bottom of the insulation plate 122, for each point electrode 115 drills through the insulation plate 122 to the later position of the respective point electrode 115 made so that at the end of each punctiform electrode, which adheres to the insulation board with conductive adhesive, an associated socket for receiving a pin from the Plug-in device 123 is created. Subsequently, a metallic plate or foil of the selected electrode material with the desired outside diameter or thickness parameters on a plate of insulating material with a thickness according to the desired thickness of the insulation plate 122 glued. Then a material removal takes place from the metallic Electrode foil for forming the point electrodes 115, wherein the corresponding positions of the point electrodes over the holes be arranged in the insulation plate. For material removal become channel-shaped free spaces according to the pattern of the isolation webs 116 (see Fig. 6) is formed. This material removal takes place for example by a masked etching process, in which the metallic foil except at the desired positions the Punktelektrcden continuously up to the insulation plate is removed. Subsequently, the channels are formed the insulating webs 116 filled with an insulating material. This is done for example by pouring with a curable Resin.

In alternative procedures are with appropriate Patterning Method Jacks in Isolation Plate 122 formed, each closed to the adaptive electrode and electrically connected to the respective point electrode 115 are. In any case, the segmented electrode forms a vacuum-tight closure of the reaction space.

At the side facing away from the segmented electrode of the Plug units 123 are boards 124 attached, the connector 126 to external electronics and address decoder, Multiplex and demultiplex circuits 127, 128, 129 carry, their functions will be explained in detail below with reference to FIG. 8 becomes. In the illustrated embodiment of the invention are four connector units 123 (including the boards 124) for each 2 × 32 point electrodes 115, each with one MUX module combined to control 8 x 32 point electrodes. The distance between the four corresponding boards 124 becomes determined by the grid dimension and is slightly larger than the height of the attached circuits 127, 128, 129. Again This dimensioning can be changed depending on size and application become. The four boards 124 are z. T. conductive Stabilization units 126a connected to each other.

For simplified handling (equipping the segmented Electrode with plug units) can be found at the bottom of the Isolation plate 122 for each electrode subunit 113 a Color coding 117 may be provided. The boards 124 are such designed so that the illustrated in Fig. 8 electronic Switching elements can be integrated.

In the following, the electrical control of the adaptive electrode 11 according to the invention will be explained with reference to the block diagram of FIG. Fig. 8 shows in the reaction vessel 20 (see Fig. 5) point electrodes 115 as part of the RF electrode (adaptive electrode 11) and the counter electrode 12 (see also, for example
Fig. 1). Of the (total 256) point electrodes 115 of an electrode subunit 113, the first and last dot electrodes of each of the first and fourth boards 124 are enlarged (matrix positions (1,1), (2, 64), (7,1), (8, 64)). Further, the ring electrode 112 is shown.

The electronics section 130 includes all boards 124 (see FIG. Fig. 7) associated with the point electrodes 115. exemplary Here is a board 124 for 8 x 32 point electrodes 115 shown. The electronics area 130, that of the reaction space represents the opposite rear side of the adaptive electrode 11, is used to avoid excessive pressure the adaptive electrode 11 is subjected to a negative pressure. The pressure in the electronics area 130 may, for example, in the range from 10 to 100 mbar. Alternatively, the electronics area for pressure relief of the adaptive electrode too with an insulating liquid, such as. As an oil poured out be, which can also take over a cooling function. from Electronics area 130 are separated under atmospheric conditions Supply circuits 140 and a control device 150 provided. The supply circuits 140 include an RF generator 141, a supply voltage circuit 142 for the ring electrode 12, and a control voltage circuit 143rd

The board 124 has a coupling circuit 131 for each of the dot electrodes 115. The coupling circuit 131 is provided to connect each dot electrode (or generally each electrode segment) of the adaptive electrode 11 simultaneously with the output voltage of the HF generator 141 and with a segment-specific output voltage of the control voltage circuit 143 to act on. In this case, the fact is exploited with particular advantage that the RF supply high-frequency and the location-selective generation of a field distribution in the reaction chamber is low-frequency or with a static electric field. Thus, the output parameters of the RF generator 141 are, for example, an output frequency in the MHz range (corresponding to the usual frequencies for generating and maintaining plasmas, eg 12 to 15 MHz) and a voltage range of ± 150 V _SS (sinusoidal). On the other hand, the charging of the point electrodes 115 with control voltages takes place at low frequency (≦ 100 Hz) or statically (DC voltage, DC). Accordingly, each injection circuit 131 includes a capacitor-resistor combination (C1-C256, R1-R256), wherein the RF power is coupled in common across all the capacitors.

On each board is also an addressing circuit 132 provided the above (see Fig. 7) address decoder, Multiplexer and demultiplexer circuits 127, 128, 129, which work together as follows.

The address decoder circuit 127 selects in response to the switching signals (DEMUX CONTROL and MUX CONTROL) of the control circuit 150 with a switching frequency of 256 kHz, which Voltage value from the control voltage circuit 143 with the Multiplex circuit 128 to a central line 133 and from this with the demultiplexing circuit 129 on one, turn selected by the address decoder circuit 127, Einkoppelkreis 131 is switched according to a dot electrode 115. at The illustrated embodiment provides the control voltage circuit 143 sixty-four control voltage values corresponding to on sixty-four supply lines (see also Fig. 8). The control voltage values on the power supply bus 143a differ, for example, with voltage steps of 0.625 V and cover the range of ± 20 V (DC). Accordingly, the multiplexing circuit 128 makes a 1: 64 selection to connect one of the sixty-four supply lines 143a with the central line 133. In the illustrated Embodiment are further 256 Einkoppelschaltkreise 131 provided corresponding to the 256 point electrodes 115, so that the demultiplexing circuit 129 is a 256: 1 selection of the Central line 133 to one of the coupling circuits 131st meets.

The dot electrodes 115 belonging to a board 124 (corresponding to FIG an electrode subunit) are preferably serial activated according to a specific sequence pattern. In this case, with particular advantage, a dual function of the coupling capacitors C1-C256 used. These serve namely not only the coupling of the RF power, but also the Maintaining the electrode potential at the individual Point electrodes, as long as according to the serial drive sequence no connection with the control voltage circuit 143 consists. Because of each point electrode 115 continuously by power losses over which plasma a performance loss arises are the coupling capacitors C1-C256 cyclically to the desired Recharge voltage value. The coupling capacitors are designed so that at the application-dependent electrode voltages or losses the charge loss at the respective Einkoppelkondensator and thus the voltage drop at the associated Point electrode during a drive cycle (≤ 1%) with respect to the electrode voltage.

The switching frequency of the address decoding circuit 127 becomes depending on the number of belonging to a subunit 113 Point electrodes 115, of the frequency of the control voltage changes and of the constant voltage during a Cycle at the point electrodes chosen so that the serial cycle run by the subunit or segment group 113 a much higher frequency than the low frequency voltage of Control voltage change has. This means for example at 256 point electrodes and a desired cycle frequency of about 1 kHz (corresponding to 1,000 reloads per dot electrode per second) a switching frequency of 256 kHz. This fast switching between the voltage stages of the control voltage circuit 143 also allows a location-selective modeling of the field profile in the reaction space 20 according to a Alternating field behavior.

The entire control electronics 140, 150 of FIG. 8 is potential superimposed on the RF signal and therefore circuit technology low in capacity from the control computer, the network and others Interfaces for cooling etc. decoupled. The entry of Control signals via the control device 150 preferably takes place via an optocoupler.

The above-described adaptive electrode 11 and its associated Control electronics can be modified as follows. The Number, shape and arrangement of the electrode segments can be application-dependent to be changed. When realizing a matrix With point electrodes, the summary can be in segment groups be changed depending on the application. The same applies to the voltage range of the control voltage circuit 143 and the Size of adjustable voltage steps or steps. Finally, the structure in the reaction vessel (see Fig. 5) can be reversed by placing the grounded electrode 12 on the bottom and the RF electrode 11 (specifically, the adaptive electrode 11) on the upper side.

The most important advantage of the adaptive electrode 11 is the Creating a programmable spatial stationary or low-frequency electric field course in the reaction space, held in place with the charged particles or can be moved in a certain way. Thereby are the particles to be manipulated can be positioned in any desired manner.

Fig. 9 shows a schematic side view of parts of a Arrangement according to the invention, in which the plasma crystal 50 between the RF electrode 11 and the substrate 30 with the adjusting device 31 on the one hand and the counter electrode 12 on the other is stepped. This plasma crystal form can be, for example, by using an unloading device achieve according to FIG. 2. By a partial irradiation the plasma crystal with UV light becomes a part of the particles (in Fig. 9, the left area) discharged, so that the Equilibrium at unchanged plasma conditions in a low Height above the RF electrode 11 is set. By a corresponding change in the relative position of the plasma crystal 50 and / or the substrate 30 can be a partial Achieve coating of the substrate 30, as in the lower part of Fig. 4 is illustrated.

By structuring the HF electrode 11 with structural elements 61 of FIG. 10, the electric field between the HF electrode 11 and the counter electrode 12 influenced in such a way be that the plasma crystal with only in one area a minimum of potential that spreads over the parts of the RF electrode 11 is located, not by the structural elements 61 are covered. If the structural elements 61 become, for example formed by cover bars, which form a strip-shaped gap let the plasma crystal 60 has a stripe shape (Extension direction perpendicular to the plane of Fig. 10). The plasma crystal 60 can again be inventively deposit on the substrate 30. Alternative to the stripe design 10, the RF electrode 11 can be with structure or mask any structural elements 61.

Fig. 11 shows an additional possibility of exercising external Forces on a plasma crystal. The schematic plan view to an inventive arrangement shows the RF electrode 11th with the control device 13 and the substrate 30 with the adjusting device 31. The RF electrode 11 carries structural elements (not shown) of FIG. 10, so that a strip-shaped Plasma crystal forms. The shape of the plasma crystal 70 can be further modified by deflection electrodes 71 are acted upon synchronously with an AC voltage. The deflection electrodes 71 are at a lateral deflection of a layered plasma crystal arranged in the layer plane. Thus, for example, a serpentine Achieve vibration of the particles, as in the lower part of Fig. 11 is sketched. This crystal arrangement can turn be removed on the substrate 30.

In Fig. 12 is a surface coating with elongated Particles shown in particular to achieve anisotropic optical surface properties is set up. The elongated particles are, for example, so-called Bucky-Tubes (microscopic, tubular particles consisting from a regular array of carbon atoms). The For example, Bucky tubes may be a few microns in length and have a diameter of about 10 to 20 nm. These particles have a relatively large surface, that lead to a heavy charge in the plasma and one Polarization leads. In the plasma crystal 80 are the Bucky Tubes regularly with their longitudinal extent perpendicular to the planes aligned with the discharge electrodes. By an appropriate Approaching the substrate 30, the adsorption of the elongated particles with a vertical preferred direction, as illustrated in the lower part of FIG. 12. These adsorbates may optionally in an additional step in their Location can be fixed by an additional coating.

According to Fig. 13, which is a plan view of parts of an inventive Arrangement shows is a manipulation of the plasma crystal 90 also by applying a radiation pressure of one outer light source 91 possible. The outer control light source For example, by a helium-neon laser with a Power of about 10 mW are formed. The one with the laser beam Radiation pressure exerted on the particles allows a precise position control, with an observation device 17 (see Fig. 1) can be monitored. With the help of Radiation pressure can be a plasma crystal preferably Turn (see arrow), or even on a laterally arranged Move the substrate.

Besides the illustrated embodiments of the invention further modifications of the inventive arrangement Establishment of means conceivable with which by exercising external Forces the conditions of a plasma crystal in a location-selective manner can be changed. For example, it is possible In addition, a magnetic field device for targeted control of the plasma, for example, by a perpendicular to the electrode planes to achieve aligned magnetic field direction. It it is also possible, the coating process dynamic to carry out, whereby continuously particles to the plasma space fed and location-selective by arrangement as a plasma crystal be applied to the substrate surface. Further modifications refer to the substrate. The substrate must not be flat, but may have a curved surfaces. There may be several substrates. It is also possible, a device according to the invention without application to operate on a substrate as a display device, in the anisotropic particles for displaying predetermined patterns can be switched between different orientations, for example each one state "blackening" or "transparency" represent. It is also possible to have different sizes To manipulate particles at different heights of a plasma and laterally with excitation light sources of different wavelengths to illuminate, so that color displays high resolution can be built.

A particular advantage of the invention is that they by an inexpensive modification of conventional plasma reactors (e.g., from circuit fabrication) can, whose operating conditions are well known and controllable are. The invention is for the production of so-called designer materials usable with special surface properties.

Claims (15)

1. Method for the manipulation of particles (10, 40, 50, 60, 70, 80, 90), which are arranged in a plasma of a carrier gas in a plasma-crystalline state,
   characterised in that a distance between the particles and a substrate surface is reduced so that the particles are applied at least partially on the substrate surface (30).
2. Method for the manipulation of particles (10, 40, 50, 60, 70, 80, 90), which are arranged in a plasma of a carrier gas in a plasma-crystalline state,
   characterised in that the particles are at least partially subjected to a plasma treatment in the form of a plasma coating or removal.
3. Method according to Claim 2, wherein the particles are moved into a treatment position for the plasma treatment at least partially through an application of external displacement forces and/or a change in the plasma conditions.
4. Method according to Claim 3, wherein after the plasma treatment the particles are applied at least partially on a substrate surface (30).
5. Method according to Claim 1 or 4, wherein a distance of the particles from the substrate surface is changed through a movement of the substrate surface, an application of external displacement forces and/or a change in the plasma conditions, until the particles adhere at least partially on the substrate surface.
6. Method according to one of Claims 2 to 5, wherein the external displacement forces are caused by a location-selective particle discharge or a light radiation pressure.
7. Method according to one of Claims 3 to 5, wherein the change in the plasma conditions comprises a change in plasma pressure, plasma temperature, carrier gas, plasma energy and/or operating frequency of the plasma, a shutdown of the plasma generation and/or an influencing of electrical fields in the region of the particles in the plasma-crystalline state.
8. Method according to Claim 7, wherein the influencing of the field comprises the adjustment of a static electrical field such that the particles in plasma-crystalline state arrange themselves along a predetermined curved surface or in a region defined in a predetermined manner.
9. Method for coating a substrate surface with particles, which are manipulated using a method according to one of Claims 1 to 8.
10. Device for the manipulation of particles (10, 40, 50, 60, 70, 80, 90), which are located in a plasma-crystalline state in the plasma of a carrier gas in a reaction vessel with flat, essentially parallel plasma electrodes (11, 12), which are fitted for the formation of a gas or glow discharge in the carrier gas, wherein at least one substrate (30) is arranged in the reaction vessel, characterised in that a field-forming electrode structuring means (41) is arranged in the reaction vessel for the location-specific deformation of the field between the plasma electrodes (11, 12) and for the location-specific manipulation of the particles in the plasma-crystalline state.
11. Device according to Claim 10, wherein the substrate is movably arranged between the plasma electrodes (11, 12).
12. Device according to one of Claims 10 to 11, which additionally has means for the location-selective particle discharge, means for exerting a radiation pressure and/or observation means.
13. Device according to Claim 10, wherein the electrode structuring means is formed by a high-frequency electrode system, which is configured in a reaction vessel for the generation of a field distribution and has a plurality of electrode segments, which are fitted to be subjected jointly to a high-frequency voltage to generate or maintain a plasma state in the reaction vessel and respectively individually subjected to a specific a.c. or low-frequency voltage to generate a static or slowly varying field distribution in the reaction vessel.
14. Device according to Claim 13, wherein the electrode segments form a matrix arrangement of point electrodes (115), wherein the electrode surfaces of the point electrodes are substantially smaller than the total surface of the matrix arrangement.
15. Device according to one of Claims 13 or 14, wherein the electrode segments (115) are provided on an insulation plate (122), the front side of which points to the reaction vessel for the formation of the plasma and for each electrode segment has a socket, which is respectively fitted to receive a plug unit (123), wherein each plug unit bears a printed board (124) with coupling and control circuits (131, 127, 128, 129) and the printed boards (124) are arranged in an area, which is subjected to a low pressure or is filled with an insulating liquid.

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